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Managing one Powerwall too few

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I have 38 LG320 panels (12.1 kW), APsystems YC500 microinverters & one PW2. I have been waiting 2+ years for my second PW2. When testing the PW on a sunny day, I discovered the microinverters don't ramp down but shutoff, leaving me with a counterintuitive lack of power on a sunny day. I'm looking for confirmation that my management plan, below, until I get my second PW is correct.

38 panels are arranged in three circuits. Two circuits have 13 panels (4.2 kW each) and one circuit has 12 panels (3.8 kW). The peak output of the 12.1 kW system is actually 10.0 kW at high noon. If I turn off the single 12 panel circuit, that leaves me with 26 panels outputting an actual peak of 6.8 kW. This comfortably falls within Tesla's recommendation of no more than 7.6 kW input per PW.

During grid outage, if generating more than 7 kW, turning off the 12 panel circuit is what I want to do?

Would generating high loads also work with all circuits on, i.e, turn on AC, start cooking in electric oven and on induction cooktop, etc.

I know PW output is 5 kW (7 kW momentarily). Does that have anything to do with the 7.6 kW max PV per PW?

Anybody else waiting more than two years for an extra PW2? Thanks.
 
I have 38 LG320 panels (12.1 kW), APsystems YC500 microinverters & one PW2. I have been waiting 2+ years for my second PW2. When testing the PW on a sunny day, I discovered the microinverters don't ramp down but shutoff, leaving me with a counterintuitive lack of power on a sunny day. I'm looking for confirmation that my management plan, below, until I get my second PW is correct.

38 panels are arranged in three circuits. Two circuits have 13 panels (4.2 kW each) and one circuit has 12 panels (3.8 kW). The peak output of the 12.1 kW system is actually 10.0 kW at high noon. If I turn off the single 12 panel circuit, that leaves me with 26 panels outputting an actual peak of 6.8 kW. This comfortably falls within Tesla's recommendation of no more than 7.6 kW input per PW.

During grid outage, if generating more than 7 kW, turning off the 12 panel circuit is what I want to do?

Would generating high loads also work with all circuits on, i.e, turn on AC, start cooking in electric oven and on induction cooktop, etc.

I know PW output is 5 kW (7 kW momentarily). Does that have anything to do with the 7.6 kW max PV per PW?

Anybody else waiting more than two years for an extra PW2? Thanks.
Turning off one of the PV circuits is a good idea to limit production when the grid is down. That will keep the other two circuits working until the PW is full. You could even turn off a second PV circuit if house load was light and PV generation was high.

The 5kW limit is the max the PW can consume or generate, but the 7.6kW comes from the fact that any house load will deduct from you PV generation. So if you were using 2kW in your home, and generating 7kW with PV, the PW would only have to consume 5kW to charge, which is within its limit. Adding additional load during an outage will allow more PV to generate, since it is only the difference between PV generation and house load that determines how much the PW has to consume. Many people here charge an EV during a grid outage to use excess PV generation.

You might also explore if your microinverters are capable of curtailment with the increasing frequency generated by the PW when the grid is down and the battery is nearly full. That would help by ramping down production without the need to turn off circuits.
 
@power.saver, my microinverters are not capable of curtailment.

If I understand correctly, During grid outage, PV power first goes directly to house load, leftover goes to battery, if able to take charge. If not able to take charge, everything shuts down.

Been a long time since I tested system, but thought in grid outage all PV power goes to PW, which then sends power to load. I seem to recall battery running down due to load, then battery re-charging. Then repeat.

Say I'm generating my max 10.0 kW, and my house load is 5 kW or more, am I OK to keep all PV circuits on as long as battery can accept remaining charge? If battery is full, would I need a full 10.0 kW load to keep system from shutting down? Thanks.
 
@power.saver, my microinverters are not capable of curtailment.

If I understand correctly, During grid outage, PV power first goes directly to house load, leftover goes to battery, if able to take charge. If not able to take charge, everything shuts down.

Been a long time since I tested system, but thought in grid outage all PV power goes to PW, which then sends power to load. I seem to recall battery running down due to load, then battery re-charging. Then repeat.

Say I'm generating my max 10.0 kW, and my house load is 5 kW or more, am I OK to keep all PV circuits on as long as battery can accept remaining charge? If battery is full, would I need a full 10.0 kW load to keep system from shutting down? Thanks.
Since the PV and PW are AC-coupled (all connected in parallel) the PV generation will go to the house load first, and any excess will be used to charge the PW. It doesn't go through the PW first. So as long as you keep (PV - house) < 5kW you will be okay. But once the PW are full, then you must have (PV = house) load, which is nearly impossible to manage. Best to start turning off PV circuits as the PW approach 95% and let them supply part of the house load until they drop, say to 85% when you could turn one of the PV circuits back on. But don't worry, if the PW gets full, the frequency will rise and the PV will shutdown until the PW is ready to accept more charging.
 
I have 38 LG320 panels (12.1 kW), APsystems YC500 microinverters & one PW2. I have been waiting 2+ years for my second PW2. When testing the PW on a sunny day, I discovered the microinverters don't ramp down but shutoff, leaving me with a counterintuitive lack of power on a sunny day. I'm looking for confirmation that my management plan, below, until I get my second PW is correct.

38 panels are arranged in three circuits. Two circuits have 13 panels (4.2 kW each) and one circuit has 12 panels (3.8 kW). The peak output of the 12.1 kW system is actually 10.0 kW at high noon. If I turn off the single 12 panel circuit, that leaves me with 26 panels outputting an actual peak of 6.8 kW. This comfortably falls within Tesla's recommendation of no more than 7.6 kW input per PW.

During grid outage, if generating more than 7 kW, turning off the 12 panel circuit is what I want to do?

Would generating high loads also work with all circuits on, i.e, turn on AC, start cooking in electric oven and on induction cooktop, etc.

I know PW output is 5 kW (7 kW momentarily). Does that have anything to do with the 7.6 kW max PV per PW?

Anybody else waiting more than two years for an extra PW2? Thanks.
Are you sure that your microinverters are not capable of partial curtailment either through Tesla lowering the frequency or a firmware update or alternate grid profile loaded to the micros?

Out of the box, the GW2 will shift to 65 hz and partial curtailment is only available around 60.5-62. What frequency is your microgrid when the PV goes totally off?
 
@Vines @power.saver - Maybe I'm misunderstanding curtailment. I've attached the specs for my microinverters. The YC500 does not have the ramp up/ramp down capability of the YC600 or the Enphase. I had Tesla change the frequency to 62.5 because I had some CyberPower UPS that were making noise at different frequencies (don't remember if frequency was originally higher or lower). Thanks.
 

Attachments

  • APsystems-YC500A-Datasheet-2.17.20.pdf
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@Vines @power.saver - Maybe I'm misunderstanding curtailment. I've attached the specs for my microinverters. The YC500 does not have the ramp up/ramp down capability of the YC600 or the Enphase. I had Tesla change the frequency to 62.5 because I had some CyberPower UPS that were making noise at different frequencies (don't remember if frequency was originally higher or lower). Thanks.
I am not familar with this specific micro, but I do understand that there is sometimes firmware available after the products initial launch, which makes them play nice with the Powerwall signal. Have you reached out to the manufacturer to see if they have any solutions with a new firmware for those older micros?
 
@Vines - I have not---but I will. Thanks.
This is something I just thought of and might be pretty advanced, take it with a grain of salt.

Perhaps if possible you program about (10) of your microinverters to drop out at 60.5 hz, another (9) at 61 hz and similarly the other (19) microinverters so all PV production is shutdown by the time the Powerwalls shift the frequency to 62 hz.